Some thoughts
Some of my favourite bouts of dialogue in Empire are between Han Solo and C3P0. Solo is utterly contemptuous of the protocol droid. He doesn't believe spanners should talk back. To him, 3P0 is a complete smart-arse, derisively calling him "the Professor", and snapping at him when he knows the droid is right. Han Solo does however respect Chewbacca; when C3P0 informs him that the reverse power coupling needs replacing, he bites his head off, but then quietly tells his buddy Chewie what 3P0 just told him. Solo's dislike of C3P0 may stem from the droid's own distaste at the Wookiee that Han adores. He is a positive snob when it comes to Chewbacca, and barks orders at him constantly, even calling him a "woolly" at one point. 3P0 is like Basil Fawlty. He has no respect for the lower classes, including R2D2, whom he sees as his Manuel (but in reality is more his Polly), and will not hear a bad word against his beloved Princess Leia or Master Luke. When he first meets Lando, administrator of Cloud City, his protocol-droid tongue is perched on the posterior: "Well he seems very friendly!" His reactions to Captain Solo, however, are more ambiguous. He knows he is a low-life scoundrel, but he is a superior and although he complains about him, 3P0 always tries to please him. When he walks in on Solo and the Princess just as they are getting deep down, he is brimming with excitement, and completely misreads Han's sarcastic "thank-you". In this way, their relationship is more like older, cooler brother and annoying, swotty younger brother. If the Millennium Falcon had a cinema, I think Solo would have given "goldenrod" a tenner and told him to spend the change on popcorn.
The Empire will compensate you fully if more stuff doesn't come...
The Phantom Menace -
Attack of the Clones -
Revenge of the Sith -
A New Hope -
Return of the Jedi
(April 05)